Measuring health outcomes

Negative values should be allowed in ratings of quality of life

Alexander Foss, Senior registrar

Moorfields Eye Hospital, London EC1V 2PD

EDITOR,—Ability to assess treatment and the outcomes of diseases continues to improve, and the schedule for evaluating individual quality of life developed by Anne M Hickey and colleagues clearly represents another advance.1 Accepted methodology now seems to be, however, that instruments that measure quality of life set the floor at zero (equivalent to being dead) and do not permit negative scores. This new instrument is no exception. As …